Storage-stable, functionally intact fibrinogen

1. A method for producing a fibrinogen solution from an aqueous solution containing functionally intact fibrinogen and being contaminated with contaminants including profibrin and/or fibrin monomers and/or fibrin monomer complexes and/or fibrin split products, wherein the contaminants are precipitated with a non-denaturing precipitating agent at a temperature between −4° to +4° C. and a calcium ion activity not higher than that of a 1,000 μM CaCl 2 -solution, and are separated by filtration or centrifugation from the aqueous solution.

2. A method according to claim 1 , wherein the aqueous solution has a temperature between 0° and 2° C. and an electric conductivity of <500 μS/cm when it is precipitated.

3. A method according to claim 1 , wherein the calcium ion activity is not exceeding that of a 500 μM CaCl 2 solution.

4. A method according to claim 3 , wherein the calcium ion activity is not exceeding than that of a 50 μM CaCl 2 solution.

5. A method according to claim 2 , wherein the solution has a temperature between 0° and 2° C., an electric conductivity between 10 to 100 μS/cm and a calcium ion activity not exceeding that of a 500 μM CaCl 2 solution.

6. A method according to claim 1 , wherein the fibrinogen contained in the obtained fibrinogen solution is further purified by at least one more precipitation step.

7. A method according to claim 1 , comprising obtaining a fibrinogen solution containing 0.3% to 10% clottable protein, which is storable up to 36 months at a temperature of 2° to 8° C., by removal of enzymes and their pro-enzymes which, as such or in activated form, recognize fibrinogen as a substrate, using non-denaturing precipitating agents and, optionally, by adding appropriate virus inactivated, homologous protease inhibitors.

8. A method according to claim 1 , wherein the fibrinogen solution is subjected to a method for virus inactivation or virus removal, which is carried out at temperatures above room temperature, a thrombin activity of <0.03 IE/ml and a calcium ion activity not exceeding that of a 1,000 μM CaCl 2 solution.

9. A method according to claim 8 , wherein the viruses are removed by means of nanofiltration at temperatures between 20° and 40° C. and using nanofilters with a pore size of at most 20 nm, said nanofiltration being carried out in a way so that fibrinopeptide A is not split off from fibrinogen.

10. A method for producing a fibrinogen concentrate, wherein a fibrinogen solution produced according to claim 1 is concentrated, deep-frozen or freeze-dried.

11. A method for the manufacture of a medicinal product containing a freeze-dried fibrinogen concentrate according to claim 10 and to which basic amino acids up to half of the weight of clottable protein are added, as well as salts, in order to provide osmolality, the freeze-dried fibrinogen concentrates being reconstituted in a solvent containing an amount of calcium salt ensuring that the reconstituted product has a calcium ion activity corresponding to that of a 5 mM CaCl 2 solution.

12. A method according to claim 10 , comprising heat inactivation of viruses in final containers for a period of 30 to 100 minutes at temperatures between 90° and 145° C.

13. A method according to claim 1 , wherein the calcium ion activity of the aqueous solution is lowered by adding EDTA and that glycine is used as non-denaturing precipitating agent.

14. A method according to claim 2 , wherein reduction of electric conductivity of the aqueous solution is realized by dialysis, diafiltration or alcohol precipitation in the cold.